This is just a case of taking off the fine scale wheels and axles and replacing them with Slaters. I have not even had to take any thing off of the brake blocks.
I will certainly be getting more wagons/vans from Minerva.
That looks a good job and shows S7 is not to be feared.
I found that the Minerva wheels as supplied pretty fine anyway so I simply re-gauged the to the minimum S7 back-to-back, added some crude wire springs and it seems to run well. There's a bit of a write up here Converting a Minerva Mink wagon - Scale 7 Group should you or anyone else be interested.
I have heard that the Manning Wardle is the same, the wheels work perfectly through S7 track when re-gauged. Possibly the forthcoming Class 14 also. Check first though, don't take my word for it.
Hmm, I wish I'd known that (assuming it's true) before I spent a afternoon turning down the wheels on my Manning Wardle. Ah well - it was a good learning experience.